package main

import "fmt"

func main() {
	res := sum(10, 20)
	fmt.Println("ok4 res=", res)
}
func sum(a, b int) int {
	defer fmt.Println("ok1 a=", a)
	defer fmt.Println("ok2 b=", b)
	a++
	b++
	res := a + b
	fmt.Println("ok3 res=", res)
	return res
}
